Evaluation of iron deposition in tissue is of clinical interest as many diseases influence the iron deposition in tissue or organs. Evaluation of iron deposition may be achieved through magnetic resonance imaging (MRI). MRI is a desirable technique as it is non-invasive and images an entire organ. It is known that iron deposition influences the tissue transverse relaxation values (T2 or T2*) or relaxation rates (R2=1/T2 or R2*=1/T2*), and these values can be measured by MRI. Different known methods may be used to measure pixel-wise R2 or R2* values, and corresponding T2 or T2* values, on MR images, also referred to as maps.
Different species in tissue, such as water and fat, have different R2* values. While a water R2w* value accurately reflects the iron deposition in most tissues or organs, it may be inaccurate for some regions, such as those with a high fat percentage. Typically, the iron deposition has little influence on fat R2f*. An effective R2eff* value is a R2* value of a water-fat mixture and is generally used for iron deposition evaluation. However, the effective R2eff* value also does not accurately reflect the iron deposition in regions with a high fat percentage. Therefore, radiologists or physicians may be required to read and compare the effective R2eff*, water R2w*, and fat R2f* maps side by side to evaluate the iron deposition of tissue. This is inconvenient, difficult, and confusing in practice.
This document describes a method and system for providing a clinically relevant R2CR* map based on the known values of the effective R2eff*, the water R2w*, and the fat R2f*.